I'm trying to initialize IO streams on a SAM4S in Atmel Studio 6.2.1563 (SP2). I'm aware of the stdio_serial driver in ASF, but since I'll have at least two serial ports I want to target with fprintf that doesn't seem like the way to go here. So I'm attempting to open a FILE with fdevopen or FDEV_SETUP_STREAM, just like I've done on AVRs. I've #included stdio.h, and get no errors on the include, but when I build I get the error "implicit declaration of function 'fdevopen'..." .

I can use printf with no errors (though of course it won't do anything without stdio setup), and I can right click->go to implementation and see the declaration for fdevopen, so clearly Atmel Studio is seeing it, but I guess it's not linked in properly for some reason?